OP, DO NOT credit your CI flight to DL. You get very little MQM and MQD. You are better off get into China Airlines's Emerald or Paragon. It's easier to achieve than DL and better benefits. You can SkyTeam Gold benefits system wide with CI's Emerald or Paragon.

If you go to TPE or use TPE for a transit point frequently, you are WAY better off going with China Airlines or EVA directly.

I go to TPE often and because I also need to fly a lot in the US and need to go to Europe, DL gives me a little more flexibility. I wish I can undo that decision but I am already 50k miles into it, this year...